the study states there is no difference between the nutrient values in organic vs non-organic produce : “The published literature lacks strong evidence that organic foods are significantly more nutritious than conventional foods.” However it appears some studies that do show differences were not included in the review – see Jeff Cox’s blog below

the study recognizes that pesticides are present in non-organic produce but that they are possibly nothing to be concerned about. I disagree with this and will show you the evidence.

The focus of this article is to address this statement in the conclusion: “Consumption of organic foods may reduce exposure to pesticide residues…” andwhy it’s important.

Let’s look at the some of the research around pesticide exposure and how this can affect the brain, cognition, ADHD, anxiety and depression in particular.

Organophosphates (a commonly used toxic pesticide) “act directly on the nervous system by inhibiting the neurotransmitter acetylcholine.” They have “acute psychological and behavioral effects, such as anxiety, depression, and cognitive impairments.” The researchers suggest that long-term psychological effects of low-level exposure have not been determined satisfactorily.

More recently, this study found that even low levels of pesticides in conventionally grown vegetables and fruit increased the risk of developing attention deficit/hyperactivity disorder in 8 to 15 years of age.

This study found that certain fungicides (pyrimethanil, cyprodinil and fludioxonil), alone and also in combination “showed significant reductions in cellular ATP.” “The effects on energy metabolism were reflected in their marked toxic effects on mitochondrial membrane potential.” There was also “evidence of oxidative stress.” The authors conclude: “This report suggests that the impact of some pesticides, both individually and in combinations, merits further study in terms of their impact on human cellular health.”

In this study “chronic perinatal exposure to low doses” of insecticides led to an increase in anxiety in the offspring of female mice. The authors suggest that “the routes of administration and the duration of exposure during brain development may be factors to consider when studying the development of anxiety.”

This animal study found that pesticide exposure resulted in an “increase in the levels of lipid peroxidation and reactive oxygen species in both cerebellum and cerebrum.” Also, glutathione (a potent detoxifier) was decreased and anxiety levels were increased. The interesting thing is that researchers concluded that zinc (one of my favorite nutrients for anxiety and depression) “has potential to act as a neuroprotectant against pesticide-induced neurodegenerative and behavioral disorders but further investigations need to be conducted to understand the exact mechanism of neuroprotection.”

I’m encouraged by this research and look forward to further studies that will examine the impacts of pesticides on the nervous system. So yes, we obviously do need to be concerned about pesticides in the produce we consume. This August 2012Neurotoxicology paper states it well: “The association between pesticide exposure and neurobehavioral and neurodevelopmental effects is an area of increasing concern .”

Footnote and additional reading:

This is the headline of one of the original Stanford blogs: Little evidence of health benefits from organic foods, Stanford study finds.